Search apparatus and search method

ABSTRACT

A search apparatus receives each input of a target value and a reference value indicated by the target value; generates a prediction model indicating a relation between the condition and the result based on a setting value of the condition inside the search area and a measured value of the result; acquires a prediction value from the prediction model by assigning the target value to the prediction model and specifies a presence area of the prediction value from the search area; determines whether the prediction value is closer to the target value than the reference value; sets the measured value of the result corresponding to the prediction value to the reference value when the prediction value is closer to the target value, and sets the prediction value presence area to the search area; and outputs a prediction value satisfying an achievement condition when the prediction value satisfies the achievement condition.

CLAIM OF PRIORITY

The present application claims priority from Japanese patent applicationJP 2016-184386 filed on Sep. 21, 2016, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a search apparatus and a search methodthat searches a solution.

2. Description of the Related Art

New materials for forming a semiconductor device have been introduced inorder to improve performance of the semiconductor device, andsimultaneously, a structure of the semiconductor device has beencomplicated. In addition, nanometer-level accuracy is required inprocessing of the semiconductor device. In addition, it is required tocontinue a mass production process in the state of maintaining theaccuracy as much as possible in order to improve productivity of thesemiconductor device. In order to satisfy these requests, it isnecessary for the semiconductor device to be capable of processingvarious types of materials and structures at extremely high accuracy.Accordingly, a control range of a semiconductor processing apparatus,which processes the semiconductor device, is increased, and multiplecontrol parameters are added. It is possible to produce ahigh-performance semiconductor device while maintaining highproductivity by employing the semiconductor processing apparatus.

Meanwhile, it is necessary to decide input parameters, which could beseveral types to several dozens of types for each semiconductorprocessing apparatus, in order to sufficiently draw out the performanceof the semiconductor processing apparatus. Further, there are multiplesteps in a single process, and it is necessary to change the inputparameters every step. Accordingly, it is extremely difficult toascertain combinations of the input parameters with which a targetprocessing result is obtained.

In order to maintain and improve the productivity, it is necessary toacquire a state of the semiconductor processing apparatus in the middleof producing the semiconductor device and data of a processing result. Aplurality of sensors and monitors aiming at the acquisition of such dataare mounted to the semiconductor processing apparatus. It is necessaryto analyze a relation between sensor data and monitor data, and theprocessing result and to find out a parameter for control in order toimplement control for correction of data variations in the state of thesemiconductor processing apparatus in the middle of producing thesemiconductor device and the processing result. In order to performnanometer-level processing control, the number of sensors and monitorsfor a manufacturing status, which are mounted to the semiconductorprocessing apparatus, have been increased, and a frequency of the dataacquisition has been increased. Accordingly, the amount of acquired datais increased. Accordingly, it is necessary to analyze tremendous dataand verify control performance in development of a control method forthe high accuracy semiconductor processing apparatus thus demanded,which is extremely difficult.

It is required to develop a method of aging a semiconductor processingapparatus for structures of advanced devices such as the semiconductordevice in order to secure the productivity. The method of aging thesemiconductor processing apparatus is a method of suppressing aperformance difference between semiconductor processing apparatuses,correcting a temporal change of processing characteristics duringproduction and reducing a performance difference between thesemiconductor processing apparatuses that has not been corrected bymaintenance of the semiconductor processing apparatuses. The developmentof the method of aging the semiconductor processing apparatus isimplemented by top engineers having high-level knowledge and techniques.However, the number of processed wafers and the number of highlydifficult processes keep increasing in the manufacturing of thesemiconductor device, and the shortage of top engineers becomeescalated. Thus, the number of processes in which data is acquired butthe analysis thereof is not allowed by such shortage increase.Accordingly, it is required for the semiconductor processing apparatusto have a function of automatically drawing out the performance of thesemiconductor processing apparatus by the own semiconductor processingapparatus and a function of supporting an engineer who draws out theperformance of the semiconductor processing apparatus.

JP 2013-518449 A discloses a technique of learning data at the time ofincrementally or arbitrarily changing a recipe of a manufacturing tooland generating a recipe adjusted using a result of the learning, usingan autonomous learning system based on biology.

SUMMARY OF THE INVENTION

For example, an input parameter of the semiconductor processingapparatus is a parameter that decides an operation of the semiconductorprocessing apparatus, and examples of the input parameter include a gastype, a gas flow rate, pressure, input power, a voltage, a current,processing time, heating temperature, cooling temperature, a doseamount, and a light amount. An output parameter of the semiconductorprocessing apparatus is a parameter which is obtained by monitoring ormeasuring an object to be processed (processing result), in the middleof or after being processed by the semiconductor processing apparatus,and examples thereof include a critical dimension (CD), a deposited filmthickness, an etch rate (ER), a processing shape, a mask selectionratio, and output parameters indicating processing result such as waferin-plane distribution and uniformity of these data. In addition,examples of sensor data and monitor data relating to these processingresults include a light reflection spectrum, a plasma light spectrum, awafer incident current, a wafer voltage, wafer temperature, apparatuspart temperature, and data indicating spatial distribution anduniformity of these data. The sensor data and the monitor data alsobelong to the output parameter.

It is necessary to be capable of analyzing the input and output datafrom one input and one output to multiple inputs and multiple outputs inorder to analyze a relation between the input and output of thesemiconductor processing apparatus. Further, it is necessary to search awide apparatus parameter space formed of the input parameters and theoutput parameters in order to obtain a combination of input parametersthat satisfy a target output result.

For example, it is considered a case where five basic types of inputparameters, that is, each flow rate of two types of use gases, gaspressure, discharge power, and wafer application bias power are selectedas input parameters to search. Each control range of the inputparameters is as follow. Typical ranges are set such that the controlrange of both the gas flow rates is 100 to 200 [sccm], the control rangeof the gas pressure is 1 to 10 [Pa], the control range of the dischargepower is 500 to 1500 [W], and the control range of the bias power is 0to 100 [W]. Incidentally, typical values of minimum widths at the timeof changing the respective parameters are as follow. The value of boththe gas flow rates is 1 [scorn], the value of the gas pressure is 0.1[Pa], the value of the discharge power is 1 [W], and the value of thebias power is 1 [W].

In this case, when all combinations of the control ranges of the inputparameters in the entire apparatus parameter space, that is, the numberof search conditions are roughly calculated, 100×100×100×1000×100=10¹¹is obtained. When the time taken for one-time search is about oneminute, it takes 100 thousand years or more for the entire search of thetotal number of search conditions, and the execution thereof isimpossible.

In addition, when a setting number of a value for each input parameterin one set of search is set to ten, the number of combinations of theinput parameters in the search is 10⁵. When the time taken for one-timesearch is about one minute, it requires time corresponding to two monthsor more for one set of search. It is necessary to set the time taken forone set of search to be several days or less, and desirably one hour orless at the longest in order to reach a target solution by repeating thesearch and analysis of search results. Accordingly, the setting of theinput parameters in the search, that is, decision of the search area isextremely important in order to reach the target solution.

When 2000 conditions are searched during a day by setting the number ofsearch conditions during one set of search to 100 conditions and thesearch time to one hour and repeating the search, an area of 0.000002%of the number of conditions of the apparatus parameter space of 10¹¹ issearched in a day. When such search is continued for one month, that is,60 thousand sets of search are executed, an area of 0.00006% of theapparatus parameter space is searched. Accordingly, when a search areais arbitrarily changed in a case where the search area in one set ofsearch is narrow, the possibility of reaching an optimal solution isextremely low. In addition, the time required to reach the optimalsolution is further increased when there is an overlapping search area.

Further, the relation between the input and output of the semiconductorprocessing apparatus is non-linear in most cases, and multiple localsolutions are present in the apparatus parameter space. Thus, it isextremely rare to find out values of input parameters that satisfiesvalues of output parameters through one time of data analysis andestimation. When a case where approximately one local solution ispresent in a search area of 1% of the apparatus parameter space isconsidered, the local solution is obtained with a probability of 99%even if it is assumed that an optimal solution in the search area or inthe vicinity of the search area is obtained in a case where the searcharea is set to a narrow area and the search area is arbitrarilyselected. Accordingly, it is necessary to decide the search area so asto enhance the possibility of efficiently avoiding the local solution orallowing the reaching to the solution after reaching the local solution.

However, the above-described technique in JP 2013-518449 A has a problemthat the possibility of reaching an optimal solution which is an inputparameter serving as a solution is extremely low since the recipe isjust incrementally or arbitrarily changed at the time of data learning.In other words, there is a problem that the possibility of reaching thelocal solution which is an inferior result as compared to the optimalsolution becomes extremely high.

An object of the present invention is to achieve efficiency in operationof a semiconductor processing apparatus.

A search apparatus and a search method serving as an aspect of eachinvention disclosed in the present application are configured: toreceive each input of a target value, which indicates a condition to beset in a semiconductor processing apparatus to process a semiconductoror a result obtained by processing the semiconductor using thesemiconductor processing apparatus, a reference value of the conditioninside a search area defined by ranges of the condition and the result,and the result, the reference value indicated by the target value; togenerate a prediction model indicating a relation between the conditionand the result based on a setting value of the condition inside thesearch area, a measured value of the result obtained when the settingvalue is assigned to the semiconductor processing apparatus; to acquirea prediction value from the prediction model by assigning the inputtarget value to the generated prediction model and specify a presencearea of the prediction value from the search area; to determine whetherthe measured value of the result corresponding to the prediction valueis closer to the target value than the input reference value; to set themeasured value of the result corresponding to the prediction value tothe reference value when it is determined that the measured value of theresult corresponding to the prediction value is closer to the targetvalue, and sets the prediction value presence area to the search area;and to output a prediction value satisfying an achievement conditionwhen the measured value of the result corresponding to the predictionvalue satisfies the achievement condition of the target value.

According to a representative embodiment of the present invention, it ispossible to achieve the efficiency in operation and optimization ofprocessing of the semiconductor processing apparatus. Other objects,configurations, and effects which have not been described above becomeapparent from embodiments to be described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating a search example of aninput parameter;

FIG. 2 is an explanatory diagram illustrating a system configurationexample of a semiconductor manufacturing system;

FIG. 3 is a block diagram illustrating a hardware configuration exampleof a search apparatus;

FIG. 4 is a block diagram illustrating a functional configurationexample of the search apparatus;

FIG. 5 is a first flowchart illustrating a procedure example of acontrol process of a semiconductor processing apparatus;

FIG. 6 is a second flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus;

FIG. 7 is a third flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus;

FIG. 8 is a fourth flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus;

FIG. 9 is a flowchart illustrating a method of suppressing an apparatusdifference; and

FIG. 10 is a flowchart illustrating a method of correcting a temporalchange.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

<Search Example of Input Parameter>

FIG. 1 is an explanatory diagram illustrating a search example of aninput parameter. FIG. 1 illustrates an example of a combination betweeninput data and output data with respect to a semiconductor processingapparatus at the time of searching the input data (a value of theabove-described input parameter) that enables the output data (a valueof the above-described output parameter), which satisfies a target, tobe obtained in the semiconductor processing apparatus.

Here, the semiconductor processing apparatus is an apparatus thatprocesses a semiconductor or a semiconductor device including thesemiconductor. To be specific, examples of the semiconductor processingapparatus include a lithographic apparatus, a film forming apparatus, apattern processing apparatus, an ion implanting apparatus, a heatingapparatus, and a cleaning apparatus. Examples of the lithographicapparatus include an exposure apparatus, an electron beam drawingapparatus, and an X-ray drawing apparatus. Examples of the film formingapparatus include a vapor deposition apparatus using chemical vapordeposition (CVD) or physical vapor deposition (PVD), a sputteringapparatus, and a thermal oxidation apparatus. Examples of the patternprocessing apparatus include a wet etching apparatus, a dry etchingapparatus, an electron beam processing apparatus, and a laser processingapparatus. Examples of the ion implanting apparatus include a plasmadoping apparatus and an ion beam doping apparatus. Examples of theheating apparatus include a resistance heating apparatus, a lamp heatingapparatus, and a laser heating apparatus. Examples of the cleaningapparatus include a liquid cleaning apparatus and an ultrasonic cleaningapparatus.

FIG. 1 illustrates a graph 100 having two-dimensional coordinate planewith two axes of an X1-axis and an X2-axis. An axis orthogonal to thecoordinate plane is set as a Y-axis. The X1-axis is a coordinate axis ofan input parameter X1, which serves as input to the semiconductorprocessing apparatus, and the X2-axis is a coordinate axis of an inputparameter X2 which serves as input to the semiconductor processingapparatus. Input data x1n (n=1, 2, 3, and so on) as a value of the inputparameter X1 is plotted in the X1-axis, and input data x2n as a value ofthe input parameter X2 is plotted in the X2-axis. The graph 100expresses output data in the Y-axis in each area decided by the inputdata x1n and x2n using contour lines. For example, an area includingoutput data y1 is set as a maximum value (that is, an optimal solution),and an area including output data y13 is set as a minimum value. Inaddition, the X1-axis is divided into three to obtain areas x1a, x1b andx1c in the graph 100. Similarly, the X2-axis is divided into three toobtain areas x2a, x2b and x2c in the graph 100.

For example, when an area where the output data is the highest, that is,a combination of the input data x1n and x2n, which allows the outputdata y1 to be obtained, is searched as a target, an inclination ofoutput data yn in the apparatus parameter space may be acquired as ananalysis method, and the search may be conducted in a direction in whichthe output data yn increases.

However, when the output data at this time does not include output datain the area decided by the input data x1a and x2b, the search proceedstoward output data y4′ at a vertex serving as a local solution. Inaddition, when an input parameter that needs to be searched depending ona result thereof is decided, output data in the vicinity of the outputdata y4′ is intensively acquired, and an input parameter, which allowsthe output data y4′ or output data significantly close to the outputdata y4′ to be obtained, is found. That is, it is difficult to findinput data as an optimal solution, which corresponds to the output datay1, even if repeating analysis using a value of the input parameteracquired by the search and acquisition of a value of the outputparameter obtained through the additional search.

In addition, when multiple local solutions are present around the outputdata y1 or in other areas, there is a possibility that the search fallsinto the local solution and it is difficult to find the output data y1if the acquired value of the input parameter is too small with respectto a breadth of the apparatus parameter space. In addition, it isassumed that an area of parameters x13 and x23 is estimated as an areawhere an estimated solution is present. Thereafter, if the search areais limited to a tiny area such as a part of the area defined by theparameters x13 and x23 as in JP 2013-518449 A, the inclination of theoutput data yn is significantly small, and thus, there is a possibilitythat the number of times of search until arriving at the output data y1becomes enormous and the search fails. In addition, there is apossibility that the search fails as the inclination of the output datayn is buried in noise included in the output data yn. A poor result isinevitably obtained from estimation of a solution if the quality of theoutput data yn serving as an analysis target is poor, and thus, it isnecessary to designate a search space for acquisition of data withfavorable quality which enables approximation to the solution in orderto succeed in the search.

In FIG. 1, the three parameters of x1n, x2n and yn are used. There aremultiple input and output parameters in an actual semiconductorprocessing apparatus, and thus, a vast apparatus parameter spaceobtained by multidimensional vectorization of indices of the respectiveaxes of FIG. 1 is searched. Accordingly, it is necessary to designate anapparatus parameter space in order to acquire data with favorablequality which enables efficient approximation to the solution from sucha vast apparatus parameter space. In addition, a relation between theinput and output of the semiconductor processing apparatus is non-linearin most cases, and multiple local solutions are present in the apparatusparameter space.

In this embodiment, an experiment condition for search of an apparatusparameter space is automatically decided upon consideration of ananalysis result of input and output data of the semiconductor processingapparatus, verification of an experiment result is automaticallyperformed, and these automatic operations are repeated. Accordingly, theapparatus parameter space is searched, and an optimal solution isefficiently acquired. That is, a value of an input parameter, whichallows a value of an output parameter indicating a state of thesemiconductor processing apparatus and a processing result serving astargets to be obtained, is efficiently found.

<System Configuration Example>

FIG. 2 is an explanatory diagram illustrating a system configurationexample of a semiconductor manufacturing system. A semiconductormanufacturing system 200 includes a semiconductor processing apparatus201, an apparatus control system 202, a monitor system 203, a sensorsystem 204, a database 205, and an automatic control system (searchapparatus) 206.

The semiconductor processing apparatus 201 is the apparatus thatprocesses a substrate such as a wafer or the semiconductor device asdescribed above. The semiconductor processing apparatus 201 is connectedto the apparatus control system 202, the monitor system 203, and thesensor system 204.

The apparatus control system 202 is a system that controls thesemiconductor processing apparatus 201 during running and processing ofthe semiconductor processing apparatus 201. The apparatus control system202 includes an input interface, such as a GUI, and controls executionof the semiconductor processing apparatus 201 using a value of an inputparameter input via the input interface. In addition, the apparatuscontrol system 202 includes a network interface and acquires a value ofan input parameter from an external computer and the database 205 viathe network interface.

The apparatus control system 202 includes a recipe setting controller221, an apparatus basic setting controller 222, and a setting errordetection system 223. The recipe setting controller 221 sets an inputparameter that decides an operation during the processing of thesemiconductor processing apparatus 201 and a value of the inputparameter to the semiconductor processing apparatus 201. The apparatusbasic setting controller 222 sets an input parameter that allows therunning of the semiconductor processing apparatus 201 and a value of theinput parameter to the semiconductor processing apparatus 201.

The setting error detection system 223 determines whether it is possibleto actually set the input parameter to the semiconductor processingapparatus 201 at the time of setting the input parameter in theapparatus basic setting controller 222. To be specific, for example, thesetting error detection system 223 determines whether an input parameterthat has been input is within a range of enabling the input and it is acombination of values of input parameters that enables the operation ofthe semiconductor processing apparatus 201. When a value of the inputparameter that is hardly set or a combination of such values isdetected, the setting error detection system 223 reports this settingerror to an engineer or an upper-level system to which the semiconductorprocessing apparatus 201 is connected. When the setting error isgenerated, a stop of changing of the input parameter that has been inputor a stop of the processing using the value of the input parameter thathas been input is recorded as log data.

The monitor system 203 is a system that monitors or measures an objectto be processed (processing result) which is in the middle of beingprocessed or has been processed by the semiconductor processingapparatus 201 to acquire monitor data. The monitor system 203 includesan optical monitor, a processing dimension measurement apparatus usingan electronic microscope, a temperature measurement apparatus usinginfrared light, a defect detection apparatus using a Kelvin probe forcemicroscope, and a prober apparatus that evaluates electricalcharacteristics of the object to be processed. For example, the monitorsystem 203 acquires a processing shape of the object to be processed, athickness of a film to be processed, and a processing defect as themonitor data by measuring reflection, transmission, absorption, and apolarization spectrum at the time of causing light, laser light, andX-ray to be incident to the object to be processed. It is unnecessaryfor the monitor system 203 to be directly connected to the semiconductorprocessing apparatus 201, and a measurement result may be acquired bytransporting the object to be processed to the monitor system 203 andthe result may be saved in the database 205.

The monitor system 203 monitors a medium which is used in processing ofa plasma, a gas, a liquid, and the like, which act on the object to beprocessed during the processing, and a product generated by theprocessing. These medium and product are substances that directly actwith the object to be processed or are generated as a result of theaction. The monitor system 203 includes a plasma-emission monitor usingoptical spectrum measurement, a sediment monitor, which uses an infraredspectroscopic measurement, inside a processing chamber, a monitor foratoms and molecules, discharged from the object to be processed, using amass spectrometer, and a monitor for electrical characteristics insidethe processing chamber using a probe. The monitoring using thesemonitors can measure the monitor data, which enables indirect evaluationof the processing result, in real-time and during the processingdirectly at a processing site.

The sensor system 204 is a system that acquires sensor data whichindicates an apparatus state of the semiconductor processing apparatus201. The sensor system 204 is an assembly of sensors. The sensor dataincludes power output values, such as a voltage, a current, and power,values of variable electrical elements, such as a capacitor and a coilinside the matching device, each flow rate of various use gases, eachtemperature of an apparatus framework and apparatus components, pressureinside the processing chamber, an opening degree of a pressure controlvalve, a valve opening and closing state, gas exhaust speed, andoperation timing and operation time of processing and the apparatus.

The database 205 saves values of various input parameters set by theapparatus control system 202, a value of the output parameter serving asthe processing result from the semiconductor processing apparatus 201,and the monitor data and the sensor data acquired by the monitor system203 and the sensor system 204. In addition, the database 205 saveslearning data. The learning data is input and output data serving as acombination of a value (input data) of an input parameter, which hasbeen assigned to the semiconductor processing apparatus 201 in the past,and a value (output data) of an output parameter output from thesemiconductor processing apparatus 201. The database 205 may be thedistributed database 205 which saves various types of data to be savedin different storage devices 302. A distributed database in a mode ofsaving information to be handled by each system in each system may beconstructed.

The automatic control system 206 searches a solution that satisfies atarget using the data saved in the database 205. The solution thatsatisfies the target is a value of at least one parameter among thevalue of the input parameter used for the running of the semiconductorprocessing apparatus 201 and the value of the input parameter used forthe operation during the processing of the semiconductor processingapparatus 201. The automatic control system 206 includes a targetsetting controller 261, an autonomous search system 262, and an unstableoperation detection system 263.

The target setting controller 261 receives an input of the values of theinput parameters and the value of the output parameter serving as thetarget, and an allowable value of a difference or a divergence between asearch result and the target, as initial values before starting thesearch. In addition, the target setting controller 261 can receive aninput of an upper limit of time to execute one condition in the search,the number of times of search, an upper limit of the total time takenfor one set of search, an upper limit of the total time taken for theentire search, an upper limit of time for analysis of a search result,and an upper limit of the number of analysis data. In addition, thetarget setting controller 261 can set the availability of search withrespect to the respective input parameters and set an upper limit valueand a lower limit value of a control range of the input parameter tosearch and values to limit the control range of the input parameter tosearch. Further, the target setting controller 261 can receive an inputof an optimal solution before starting the search which includes a pastresult, analysis target data which has been used to obtain the solution,and a model function describing a relation between a target obtained bythe analysis and the input parameter.

The autonomous search system 262 acquires content that has been input tothe target setting controller 261 and sets division areas, which areobtained by dividing the control range of the input parameters that canbe searched into two or more areas, with respect to one or moreparameters. As described above, it is necessary to set the time takenfor one set of search to be several days or less, and desirably one houror less at the longest in order to reach a target solution by repeatingthe search and analysis of search results. That is, when the number ofsearch conditions for one set of search is Ns, search time taken for oneset of search is Ts [min], and time required for one search condition ist1 [min], the number of times of search is given as Formula (1.1).

Ts=t1·Ns  (1.1)

When the number of search conditions Ns may be decided such that Ts≤1440in the case of finishing one set of search within a day, or Ts≤60 in thecase of finishing one set of search within an hour.

It is effective to shorten each measurement time of the sensor and themonitor, which evaluate the search result, in order to increase thenumber of search conditions Ns. In particular, it is effective to usethe sensor and the monitor which can perform the measurement inreal-time in the search experiment.

In addition, it is possible to perform the measurement in real-time andduring the processing directly at the processing site by measuringcharacteristics of the medium acting on the object to be processed andthe product generated by the processing, which serve as the data thatenables the indirect evaluation of the processing result, using thesensor and the monitor.

The search time Ts rapidly increases along with an increase of types ofinput parameters to be changed in the search. For example, when thenumber Da of types of input parameters is set such that Da=10 and anarea division number A of each parameter is set such that A=3, thenumber of search conditions Ns in the case of searching combinations ofall parameters is given as Formula (1.2).

Ns=A ^(Da)  (1.2)

The number of search conditions Ns is increased up to 59049. In thiscase, it is preferable to predict each value of the input parameters,predicted to have a solution, and limit the number of input parametersthat can be changed at the same time during the search using theprediction value as a center condition. Accordingly, the number ofsearch conditions Ns and the search time Ts become values that can beexecuted. It is possible to use the past search result or knowledge ofthe engineer at the time of predicting the center condition.Alternatively, it is also possible to assign a suitable center conditionas an initial value of search and start the search.

For example, when division areas, estimated to have a solution, aredesignated for five types among ten types of the input parameters, it ispossible to decrease the number of search conditions Ns in the nextsearch up to Ns=3⁵=243 by changing the other five types of the inputparameters. In addition, the number of types of input parameters thatcan be changed at once among the ten types of input parameters is set toDc. The number of search conditions Ns is obtained from Formula (1.3)using a sign C of a combination logic.

$\begin{matrix}\left\lbrack {{Formula}\mspace{14mu} 1} \right\rbrack & \; \\{{Ns} = {1 + {\sum\limits_{i = 1}^{Dc}{\left( {A - 1} \right)_{Da}^{i}C_{i}}}}} & (1.3)\end{matrix}$

It is possible to decrease the number of search conditions Ns bylimiting the input parameters that can be changed at once. For example,the number of search conditions Ns is obtained such that Ns=21 when thenumber Dc of types of input parameters that can be changed is set suchthat Dc=1. Similarly, it is possible to decrease Ns to be Ns=201 when Dcis set such that Dc=2. Further, it is also possible to combine a methodof designating the division area estimated to have the solution withseveral types of input parameters among all types of input parametersand a method of designating types of parameters that can be changed atonce.

The unstable operation detection system 263 detects a case where thesemiconductor processing apparatus 201 can continue a processingoperation but the processing is unstable at the time of executing thesearch. The setting error detection system 223 confirms whether it ispossible to input the input parameter in a stage before executing theinput of the input parameter. However, the medium and parts serving asobjects to be controlled by the devices inside the semiconductorprocessing apparatus 201 have the non-linearity, and the processing isexecuted by combining the medium and the parts. Accordingly, there is apossibility that the setting error detection system 223 fails to detectthe setting error (inability of the input of the input parameter) and aninput parameter, which causes the unstable operation for the first timeat the time of actually executing the processing is found.

In addition, the apparatus parameter space increases as the number ofinput parameters increases. Thus, when an unstable operation area islocally present in the apparatus parameter space, the possibility offailing in detection of such an area in advance becomes high.

Accordingly, when the unstable operation detection system 263 hasdetected an unstable operation of the semiconductor processing apparatus201 during the processing of the semiconductor processing apparatus 201,the semiconductor processing apparatus 201 saves an input parameter anda value thereof at the time of the unstable operation, and further,reports the result to the engineer or the upper-level system to whichthe semiconductor processing apparatus 201 is connected. Accordingly, itis possible to determine or predict an operation failure in theprocessing and search caused by the unstable operation of thesemiconductor processing apparatus 201.

When the unstable operation has been detected, a sequence forrestoration of the semiconductor processing apparatus 201 to a normaloperation state is executed after completing the processing, or theprocessing is immediately stopped and the sequence for restoration ofthe semiconductor processing apparatus 201 to the normal operation stateis executed to continue the search.

Examples of the unstable operation include abnormal discharge locallycaused during the processing, oscillation of discharge intensity, arapid variation of film forming speed and a variation of film quality,oscillation of gas pressure, instantaneous increase or decrease andoscillation of input power, and the like. The unstable operation isdetected by the above-described monitors capable of performing themeasurement in real-time and during the processing directly at theprocessing site, such as the emission spectrum monitor, the sedimentmonitor, the mass spectrometry monitor, the electrical characteristicsmonitor, and the pressure monitor.

<Hardware Configuration Example of Search Apparatus>

FIG. 3 is a block diagram illustrating a hardware configuration exampleof a search apparatus 300. The search apparatus 300 searches a value ofan input parameter serving as a solution from a search area. Theautomatic control system 206 is an example of the search apparatus 300.The search apparatus 300 includes a processor 301, a storage device 302,an input device 303, an output device 304, and a communication interface(communication IF 305). The processor 301, the storage device 302, theinput device 303, the output device 304, and the communication IF 305are connected via a bus. The processor 301 controls the search apparatus300. The storage device 302 serves as a work area of the processor 301.In addition, the storage device 302 is a non-transitory or transitoryrecording medium that stores various types of programs and data.Examples of the storage device 302 include a read only memory (ROM), arandom access memory (RAM), a hard disk drive (HDD), and a flash memory.The input device 303 inputs data. Examples of the input device 303include a keyboard, a mouse, a touch panel, a numeric keypad, and ascanner. The output device 304 outputs data. Examples of the outputdevice 304 include a display and a printer. The communication IF 305 isconnected to a network to perform transmission and reception of data.

<Mechanical Configuration Example of Search Apparatus 300>

FIG. 4 is a block diagram illustrating a functional configurationexample of the search apparatus 300. The search apparatus 300 includesan input unit 401, a generating unit 402, a specifying unit 403, adetermining unit 404, a setting unit 405, an output unit 406, a decidingunit 407, a dividing unit 408, and a detecting unit 409. To be specific,the respective configurations 401 to 409 are functions that areimplemented by causing the processor 301 to execute the program storedin the storage device 302 illustrated in FIG. 3, for example.

The input unit 401 receives an input of the various types of datathrough a user operation or reading from the database 205. To bespecific, for example, the input unit 401 receives an input of acondition value to be set to the semiconductor processing apparatus 201that processes the semiconductor device. The condition to be set to thesemiconductor processing apparatus 201 means the above-described inputparameter. To be specific, examples of the input parameter include a gastype, a gas flow rate, pressure, input power, a voltage, a current,processing time, heating temperature, cooling temperature, a doseamount, and a light amount.

In addition, the input unit 401 receives an input of a target valuewhich indicates a result obtained by processing a semiconductor usingthe semiconductor processing apparatus 201. The result obtained byprocessing of the semiconductor using the semiconductor processingapparatus 201 means the above-described output parameter. To bespecific, examples of the output parameter include the processing resultof the semiconductor using the semiconductor processing apparatus 201and the data relating to the apparatus state of the semiconductorprocessing apparatus 201. To be specific, examples of the processingresult of the semiconductor using the semiconductor processing apparatus201 include a critical dimension (CD), a deposited film thickness, anetch rate (ER), a processing shape, a mask selection ratio, and waferin-plane distribution and uniformity thereof. To be specific, examplesof the processing result of the semiconductor processing apparatus 201and the data relating to the apparatus state of the semiconductorprocessing apparatus 201 include a light reflection spectrum, a plasmalight spectrum, a wafer incident current, a wafer voltage, wafertemperature, apparatus part temperature, and data (the sensor data andthe monitor data) indicating spatial distribution and uniformity ofthese data. The target value, which indicates the result obtained byprocessing the semiconductor using the semiconductor processingapparatus 201, is a value of the output parameter of the semiconductorprocessing apparatus 201 requested by the user.

In addition, the input unit 401 receives an input of a reference valueof the condition inside a search area defined by ranges of the condition(input parameter) and the result (output parameter). The search area isan area that is defined by the control range of the input parameter andthe control range of the output parameter of the semiconductorprocessing apparatus 201 to search a value of the input parameter. To bespecific, an example of the search area is a search area A illustratedin FIG. 1. The condition reference value is a reference value of theinput parameter. To be specific, an example the condition referencevalue is a value of the input parameter obtained in the past.

In addition, the input unit 401 receives an input of a reference valueof a result inside the search area. The result reference value is avalue of the output parameter of the semiconductor processing apparatus201 when the reference value of the input parameter is applied to thesemiconductor processing apparatus 201.

The generating unit 402 generates a prediction model which indicates arelation between the condition and the result based on a setting valueof the condition inside the search area and a measured value of theresult at the time of applying the setting value to the semiconductorprocessing apparatus 201. The condition setting value is, for example, avalue of the input parameter prepared as the learning data. The measuredvalue of the result is a value of the output parameter of thesemiconductor processing apparatus 201 in a case where the value of theinput parameter (the condition setting value) prepared as the learningdata is applied to the semiconductor processing apparatus 201. Theprediction model is a function which shows a relation between the inputparameter and the output parameter. The generating unit 402 generatesthe prediction model indicating the relation between the conditionsetting value inside the search area and the measured value of theoutput by performing regression analysis capable of corresponding tomultiple inputs and multiple outputs of a neural network, a supportvector machine or the like, and statistical analysis such as correlationanalysis, principal component analysis, and multiple regressionanalysis.

The specifying unit 403 acquires a prediction value corresponding to thetarget value and specifies an area where the prediction value is presentby applying the target value input by the input unit 401 to theprediction model generated by the generating unit 402. In addition, whenthe output parameter of the prediction value presence area is notacquired, the generating unit 402 acquires the measured value of theoutput in the case of applying the condition setting value inside thedivision area to the semiconductor processing apparatus 201, for eachdivision area.

When the target value is the value of the output parameter of thesemiconductor processing apparatus 201, the specifying unit 403 appliesthe value of the output parameter to the prediction model and acquiresthe value of the input parameter from the prediction model as theprediction value corresponding to the target value. Further, thespecifying unit 403 specifies the value of an input parameter presencearea as the prediction value from the search area. To be specific, whenthe target value is a value y12 of the output parameter in FIG. 1, forexample, the prediction value corresponding to the target value y12 isvalues of the input parameters X1 and X2 which are specified by thecontour line of the target value y12 in FIG. 1. Accordingly, thespecifying unit 403 specifies areas A1, A2, A3, A8 and A9 where thevalues of the input parameters X1 and X2, specified by the contour lineof the target value y12, are present from the search area A.

The determining unit 404 determines whether a target value correspondingto the prediction value is closer to the target value than the resultreference value input by the input unit 401. To be specific, forexample, the determining unit 404 obtains a distance (first distance)between the target value corresponding to the prediction value and thetarget value, and a distance (second distance) between the resultreference value and the target value in the search area A. The distanceis, for example, Euclidean distance. When the first distance is shorterthan the second distance, the determining unit 404 determines that thetarget value corresponding to the prediction value is closer to thetarget value than the result reference value. When the first distance isnot shorter than the second distance, the determining unit 404determines that the target value corresponding to the prediction valueis not closer to the target value than the result reference value.

When the determining unit 404 determines that the target valuecorresponding to the prediction value is closer to the target value thanthe result reference value, the setting unit 405 sets the predictionvalue and the target value corresponding to the prediction value as thecondition reference value and the result reference value, and sets theprediction value presence area specified by the specifying unit 403 asthe search area. Accordingly, the reference value is close to the targetvalue, and the search area is also narrowed down to the prediction valuepresence area.

The output unit 406 outputs a prediction value that satisfies anachievement condition when the prediction value satisfies theachievement condition of the target value. The achievement condition is,for example, an allowable range of the target value. The output unit 406may display the prediction value satisfying the achievement condition onthe display as an example of the output device 304, transmit theprediction value to an external apparatus via the communication IF 305,or save the prediction value in the storage device 302 or the database205.

When the determining unit 404 determines that the target valuecorresponding to the prediction value is not closer to the target valuethan the result reference value, the deciding unit 407 decides theprediction value and the target value corresponding to the predictionvalue as exclusion data (which will be described later in step S601 inFIG. 6). The exclusion data is a value of the input parameter that isprevented from being applied to the prediction model.

In this case, the setting unit 405 further sets data except for theexclusion data decided by the deciding unit 407 as the learning data.Accordingly, the generating unit 402 can use the learning data withoutthe exclusion data. Accordingly, it is possible to achieve theimprovement in speed of searching the value of the input parameterserving as the solution.

In addition, when the determining unit 404 determines that the targetvalue corresponding to the prediction value is not closer to the targetvalue than the result reference value, the deciding unit 407 may decidethe prediction value presence area as the exclusion area (which will bedescribed later in step S602 in FIG. 6). The exclusion area is an areaof the input parameter that is prevented from being output by theprediction model.

In this case, the setting unit 405 further sets a remaining area,obtained by excluding the exclusion area decided by the deciding unit407 from the search area, as the search area. Accordingly, it ispossible to narrow down the search area by excluding a range of theprediction value with which only the result that is not close to thetarget value is obtained. Accordingly, it is possible to achieve theimprovement in speed of searching the value of the input parameterserving as the solution.

The dividing unit 408 divides the search area into a plurality of areas.To be specific, the dividing unit 408 divides the search area A intonine areas (division areas) A1 to A9 as illustrated in FIG. 1, forexample. In this case, the generating unit 402 acquires the measuredvalue of the output in the case of applying the condition setting valueinside the division area to the semiconductor processing apparatus 201,for each division area. Further, the generating unit 402 generates theprediction model based on the condition setting value and the measuredvalue of the output in each divided region. When the plurality ofsemiconductor processing apparatuses 201 are used, it is possible toacquire the measured value for each of the division areas, and toimprove a rate of generating the prediction model.

In addition, when the determining unit 404 determines that the targetvalue corresponding to the prediction value is not closer to the targetvalue than the result reference value, the setting unit 405 may set theprediction value presence area as the search area instead of setting theprediction value and the target value corresponding to the predictionvalue as the condition reference value and the result reference value(which will be described later in steps S604 to S606 in FIG. 6).Accordingly, it is possible to execute the more detailed search of thesolution and to confirm whether there is no missing solution by furthersubdividing the search area.

In addition, when the determining unit 404 determines that the targetvalue corresponding to the prediction value is not closer to the targetvalue than the reference value of the result, the deciding unit 407 maydecide the prediction value and the target value corresponding to theprediction value as the exclusion data as described above. In this case,the generating unit 402 may generate a prediction model based on aremaining measured value, obtained by excluding the exclusion data fromthe measured value, and a remaining setting value obtained by excludinga setting value corresponding to the remaining measured value from thesetting value (to be described later in FIG. 7). Accordingly, it ispossible to achieve the improvement in speed of searching the value ofthe input parameter serving as the solution.

In addition, when the determining unit 404 determines that the targetvalue corresponding to the prediction value is not closer to the targetvalue than the result reference value, the deciding unit 407 may decidethe prediction value presence area as the exclusion area as describedabove. In this case, the generating unit 402 may generate a predictionmodel based on a remaining condition setting value inside the searcharea obtained by excluding the exclusion area from the search area and ameasured value of the output at the time of applying this setting valueto the semiconductor processing apparatus 201 (to be described later inFIG. 8). Accordingly, it is possible to achieve the improvement in speedof searching the value of the input parameter serving as the solution.

The detecting unit 409 detects an unstable operation of thesemiconductor processing apparatus 201 based on the output of thesemiconductor processing apparatus 201 and a predetermined outputthreshold value. The detecting unit 409 corresponds to the unstableoperation detection system 263. In this case, the output unit 406outputs a result obtained by detection using the detecting unit 409.

<Procedure Example of Control Process of Semiconductor ProcessingApparatus 201>

FIG. 5 is a first flowchart illustrating a procedure example of acontrol process of the semiconductor processing apparatus 201. Thesearch apparatus 300 receives an output value from the semiconductorprocessing apparatus 201 as a target (target value of the outputparameter), and an input of search setting (step S501). Examples of thesearch setting include a difference between a search result and a targetvalue or an allowable value of divergence, an upper limit of time toexecute one condition in search, the number of times of search, an upperlimit of the total time taken for one set of search, an upper limit ofthe total time taken for the entire search, an upper limit of time foranalysis of a search result, an upper limit of the number of analysisdata, a threshold value of an acquisition frequency of output data fromthe semiconductor processing apparatus 201, an upper limit ofacquisition time of output data (value of the output parameter) from thesemiconductor processing apparatus 201, and a lower limit of the numberof output data from the semiconductor processing apparatus 201.

Next, the search apparatus 300 receives an input of a solution as a baseand an input of information on the solution (step S502). To be specific,for example, the search apparatus 300 receives an input of an inputparameter that has been actually used in the past, an output parameterat the time of using the input parameter, an optimal solution (value ofan input parameter) before starting search and an output parameter atthe time of using the optimal solution, a target value of an outputparameter before starting search, and a model function that describes arelation between an input parameter and an output parameter.

Next, the search apparatus 300 saves the optimal solution input in stepS502 as an optimal solution OS1 (step S503). When there is no solution,a sign or a value indicating that it is the farthest from the solutionis set.

Next, the search apparatus 300 sets a basic search area as a search area(step S504). To be specific, for example, the search apparatus 300 setsthe availability of search with respect to the respective inputparameters and sets an upper limit value and a lower limit value of acontrol range of the input parameter to search and values (for example,an upper limit value and a lower limit value) to limit the control rangeof the input parameter to search. In addition, the search apparatus 300decides the search area with reference to the control range of the inputparameter determined as the setting error by the setting error detectionsystem 223. Further, the search apparatus 300 decides the search areawith reference to the parameter detected by the unstable operationdetection system 263. In addition, the unstable operation detectionsystem 263 holds values of combinations of the input parameters causingstop or instability of the operation of the semiconductor processingapparatus 201 in the past or each input parameter range, and the searchapparatus 300 decides the search area using these values.

For example, when the two input parameters X1 and X2 are selected astypes of the input parameters in FIG. 1, the area A in the entire rangeillustrated in FIG. 1 is set as the search area if a control range ofthe input parameter X1 is set to [x11, x1n] and a control range of theinput parameter X2 is set to [x21, x2n].

Input and setting content of the target setting controller 261 in stepsS501 to S504 are handed over to the autonomous search system 262, andthe automatic search is executed by procedures in steps S505 to S510 tobe described as follow.

The search apparatus 300 divides the search area (step S505). To bespecific, for example, the search apparatus 300 divides the controlrange of the input parameter that can be searched into two or more areaswith respect to one or more input parameters. The divided area isreferred to as the division area. When the number of search conditionsincreases and it is predicted that search is hardly completed within adesired time, it is possible to limit the search area or reduce thenumber of search conditions using a method of designating a divisionarea which is estimated to have a solution in several input parametersamong the types of the input parameters, and a method of designatingtypes of the input parameters that can be changed at once. In addition,it is possible to limit the search area or reduce the number of searchconditions by combining these two methods.

For example, when the two input parameters X1 and X2 are selected astypes of the input parameters in FIG. 1, the nine division areas A1 toA9 illustrated in FIG. 1 are obtained if the control range [x11, x1n] ofthe input parameter X1 is divided into x1a, x1b, and x1c and the controlrange [x21, x2n] of the input parameter X2 is divided into x2a, x2b, andx2c.

The search apparatus 300 executes autonomous search for each divisionarea (step S506). To be specific, for example, the search apparatus 300acquires the input and output data of the semiconductor processingapparatus 201 in each search condition as a search result through theautonomous search using the division areas and the search conditions.The input and output data is a set of a value (input data) of an inputparameter assigned to the semiconductor processing apparatus 201 and avalue (output data) of an output parameter obtained from thesemiconductor processing apparatus 201.

To be specific, for example, the search apparatus 300 selects the valueof the input parameter satisfying the search condition for each divisionarea, and assigns the selected value of the input parameter to thesemiconductor processing apparatus 201. Further, the search apparatus300 acquires the output data (value of the output parameter) from thesemiconductor processing apparatus 201. This combination of the value ofthe input parameter and the value of the output parameter correspondingto the value is the search result.

In this case, the unstable operation detection system 263 furtherdetects a case where the processing operation of the semiconductorprocessing apparatus 201 can be continued but the processing of thesemiconductor processing apparatus 201 becomes unstable during theexecution of the autonomous search. When the unstable operation has beendetected, the sequence for restoration of the semiconductor processingapparatus 201 to the normal operation state is executed after completingthe processing, or the processing is immediately stopped and thesequence for restoration of the semiconductor processing apparatus 201to the normal operation state is executed to continue the autonomoussearch performed by the target setting controller 261.

The search apparatus 300 saves the search result for each the divisionarea in the database 205 (step S507). To be specific, for example, thesearch apparatus 300 saves the input and output data, which is a set ofa value of an input parameter used in the autonomous search (step S506),a value of an output parameter of the semiconductor processing apparatus201 acquired using the value of the input parameter, in the database 205as the search result for each division area.

The search apparatus 300 generates a prediction model to predict asolution (input parameter) that satisfies a target (target output) (stepS508). To be specific, for example, the search apparatus 300 generatesthe function indicating the relation between the input and output dataof the semiconductor processing apparatus 201, as the prediction model,using the learning data saved in the database 205 in step S507. It ispossible to use the regression analysis capable of corresponding tomultiple inputs and multiple outputs such as the neural network, thesupport vector regression and regression using a Kernel method as amethod of analyzing the relation between the input and output data. Inaddition, the statistical analysis, such as the correlation analysis,the principal component analysis, and the multiple regression analysis,can be used.

In the generation of the prediction model, for example, the sensor dataand the monitor data to acquire an indirect measurement value withrespect to the processing result of the semiconductor processingapparatus 201 is used as the output data. There is a case where theacquisition frequency of the output data is lower than a frequencydefined in the search setting or longer than the acquisition timedefined in the search setting, and the number of output data that can beacquired by search becomes smaller than the number of output datadefined in the search setting. In this case, the sensor data and themonitor data with which the larger number of data can be acquired thanthe number of acquired output data may be acquired. Accordingly, it ispossible to analyze a relation of the sensor data and the monitor datawith respect to the output data, and a relation of the input data withrespect to the sensor data and the monitor data. In addition, it ispossible to obtain the relation of the input data with respect to theoutput data using these both analysis results.

The search apparatus 300 estimates the division area where the solutionis present (step S509). When the output data inside the area estimatedto have the solution has been acquired (Yes in step S5090A), the searchapparatus 300 specifies an optimal solution OS2 in the estimationdivision area, and saves the estimated optimal solution OS2 in thedatabase 205 (step S510). In addition, when the output data inside thearea estimated to have the solution has not been acquired (No in stepS5090A), the search apparatus 300 executes autonomous search inside theestimated area (step S5060A), acquires the output data, that is, thesearch result inside the area estimated to have the solution, and savesthe acquired data in the database 205 (step S5070A). The autonomoussearch and the saving of the result are the same processes as those insteps S506 and S507. There are two methods of processing step S509. Oneis a method (first estimation method) of assigning the target value ofthe output parameter assigned in step S501 to the prediction model.

To be specific, for example, the search apparatus 300 estimates theinput data (value of the input parameter) which serves as the solutionsatisfying the target value of the output parameter by substituting theprediction model obtained in step S508 with the target value of theoutput parameter assigned in step S501 in the first estimation method.Further, the search apparatus 300 specifies the division area where theinput data serving as the solution is present. For example, when theprediction model is the function indicating the input and outputrelation of FIG. 1, the three division areas A1, A4 and A7 are estimatedas the division area where the solution is present among the divisionareas A1 to A9 if y6 is assigned as the target value of the outputparameter. When the output data is not acquired in the respectivedivision areas A1, A4 and A7, steps S5060A and S5070A are executed asdescribed above.

In step S510, the search apparatus 300 specifies a division area whereoutput data equal to the target value y6 is present from the acquiredoutput data, a division area where output data having a difference ordivergence between the output data and the target value that is smallerthan the allowable value (allowable value assigned in S501) is present,or a division area where output data which is the closest to the targetvalue y6, and decides this division area as an area (hereinafter,referred to as a specified division area) where the optimal solution OS2is present. When a plurality of division areas that can become thespecified division area are specified, the search apparatus 300 decidesall these areas as the division area where the optimal solution OS2 ispresent. Alternatively, the search apparatus 300 decides a division areahaving the largest number of acquired output data, which has thedifference or divergence between the output data and the target valuethat is smaller than the allowable value (allowable value assigned inS501) as the division area where the optimal solution OS2 is present,among the plurality of division areas. In the above-described example,when the acquired output data is the same as that in FIG. 1 indicated bythe prediction model, the division areas A1, A4, and A7 or the divisionarea A4 with which the value equal to y6 the value close to y6 has beenobtained is decided as the specified division area. The search apparatus300 decides the value of the input parameter at the time of obtainingthe output data that is equal to the target value of the outputparameter in the specified division area, has the difference ordivergence between the output data and the target value that is smallerthan the allowable value (allowable value assigned in S501), or is theclosest to the target value, as the optimal solution OS2.

Another method of processing step S509 is a method that can be appliedwhen it is difficult to directly obtain the input parameter serving asthe solution satisfying the target value of the output parameter bysubstituting the prediction model by the target value of the outputparameter assigned in step S501 (a second estimation method). The secondestimation method is a method of assigning multiple sets of inputparameters to the prediction model using input parameters that areassigned to the prediction model at once as one set, calculating anestimated output parameter, and acquiring a set of input parameters withwhich a result that is the closest to the target output is obtained. Forexample, the search apparatus 300 creates one or more sets of inputparameters for each division area so as to be included in each divisionarea, and assigns these sets to the prediction model, therebycalculating an output parameter at this time. It is possible to use avalue serving as a central coordinate inside the division area as theset of input parameters included in the division area as a method ofobtaining the representative estimation output for each division area.

When the calculation time becomes enormous in the case of calculatingthe estimation output by assigning extremely multiple sets of inputparameters to the prediction model, the search apparatus 300 cansuppress the calculation time by deciding the center condition of theinput parameter to be assigned to the prediction model and limiting thetypes of input parameters that can be changed from the center conditionas described using the above-described Formulas (1.1) to (1.3). Inaddition, it is possible to suppress the calculation time by limitingthe number of parameter that can be changed from the center condition atonce. Accordingly, the search apparatus 300 can obtain the inputparameter with which the result closer to the target output can beobtained while reducing the number of sets of input parameters to beassigned to the prediction model. It is possible to use the past searchresult or the knowledge of the engineer at the time of setting thecenter condition. Alternatively, it is possible to set a centralcoordinate of the entire search area as the center condition.

To be specific, the search apparatus 300 can acquire the value of theoutput parameter which serves as the prediction value by substitutingthe prediction model obtained in step S508 by the value of the set ofinput parameters in the second estimation method. For example, when theprediction model is the function indicating the input and outputrelation illustrated in FIG. 1, it is possible to obtain the estimatedoutput parameter corresponding to each input parameter when (x11, x21),(x11, x22), (x11, x23), (x12, x21), (x12, x22), (x12, x23), (x13, x21),(x13, x22), (x13, x23), (x1n, x21), (x1n, x22) and (x1n, x23) areassigned to the prediction model as the value of the input parameter.

In addition, when the output parameters corresponding to theserespective input parameters have not been acquired (Yes in step S5090A),the search apparatus 300 executes the autonomous search using therespective input parameters (step S5060A), acquires the output data,that is, the search result inside the area estimated to have thesolution, and saves the acquired data in the database 205 (step S5070A).The autonomous search and the saving of the result are the sameprocesses as those in steps S506 and S507. In addition, the processtransitions to step S510 when the output parameters corresponding to therespective input parameters have been acquired (No in step S5090A).

Further, the search apparatus 300 decides the value of the inputparameter with which the value of the output parameter serving as theprediction value that is closest to the target value of the outputparameter in the division area, for example, as the optimal solution OS2in step S510. For example, when the acquired output data is the same asthat of FIG. 1 indicated by the prediction model, a value y10 of theoutput parameter corresponding to the value (x13, x23) of the inputparameter becomes the closest value in a case where the target value ofthe output parameter is y10. Accordingly, the optimal solution OS2becomes (x13, x23). Incidentally, any of the first estimation method andthe second estimation method to be applied is set in advance.

The search apparatus 300 determines whether the value of the optimalsolution OS2 is a solution that can obtain an output parameter closer toa target than that obtained using the value of the optimal solution OS1(step S511). Further, when the value of the optimal solution OS2 is thesolution that can obtain the output parameter closer to the target thanthat obtained using the value of the optimal solution OS1 (Yes in stepS511), the process transitions to step S512. In the opposite case (No instep S511), the process transitions to step S601 (FIG. 6).

In the case of Yes in step S511, the search apparatus 300 updates theoptimal solution OS1 by setting the optimal solution OS2 as the optimalsolution OS1 (step S512). In addition, the search apparatus 300 updatesthe search area by setting the division area of the updated optimalsolution OS1 as the search area (step S514).

Thereafter, the search apparatus 300 determines whether the target hasbeen achieved (step S514). When the target has been achieved (Yes instep S514), the search apparatus 300 ends the control process. On thecontrary, when the target has not been achieved (No in step S514), theprocess transitions to step S505 or S601 (FIG. 6). Any of step S505 andS601 (FIG. 6) to which the process transitions may be set in advance ormay be selected by the user each time. Incidentally, when the target hasnot been achieved (No in step S514) and the process transitions to stepS505, the search apparatus 300 divides the updated search area obtainedin step S513 (step S505).

To be specific, for example, when the output parameter corresponding tothe updated optimal solution OS1 is equal to the target value or has adifference from the target value that is within the allowable range instep S514, the search apparatus 300 determines that the target has beenachieved (Yes in step S514). In addition, it is determined that thetarget has been achieved (Yes in step S514) when the search time set instep S501 has elapsed even if the output parameter corresponding to theupdated optimal solution OS1 is not equal to the target value or has adifference from the target value that is not within the allowable range.On the contrary, it is determined that the target has not been achieved(No in step S514) when the output parameter corresponding to the updatedoptimal solution OS1 is not equal to the target value or has adifference from the target value that is not within the allowable range,and the search time set in step S501 has not elapsed.

FIG. 6 is a second flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus 201. Thesearch apparatus 300 decides the search data inside the division areaobtained in step S509 as exclusion data (step S601). To be specific, forexample, the search apparatus 300 decides the input data (value of theinput parameter) inside the estimated area and the output data (outputparameter) as the exclusion data. The exclusion data is data having thepossibility of being excluded in the current or subsequent process(exclusion from data serving as an actual analysis target is executed inS703 in FIG. 7 or S608 in FIGS. 6 to 8). Similarly, the search apparatus300 decides the division area obtained in step S510 as an exclusion area(step S602). The exclusion area is an area having the possibility ofbeing excluded in the current or subsequent process (exclusion from dataserving as an actual analysis target is executed in S803 in FIG. 8 orS608 in FIGS. 6 to 8).

Thereafter, the search apparatus 300 determines whether to divide thedivision area obtained in step S509 (step S603). The process transitionsto step S604 in the case of dividing the area (Yes in step S603), andtransitions to step S608 in the case of not dividing the area (No instep S603).

To be specific, for example, the search apparatus 300 determines whetherto divide the division area depending on presence or absence of an inputof a division instruction from the user in step S603. In addition, thesearch apparatus 300 may forcibly divide the division area (Yes in stepS603).

Thereafter, the search apparatus 300 generates the prediction model(step S604) similarly to step S508. Next, the search apparatus 300estimates the division area where the solution is present from adivision area group divided in step S603 (step S605) similarly to stepS509. The estimated division area is referred to as the estimationdivision area. Further, the search apparatus 300 executes the sameprocesses as those in steps S5090A, S5060A and S5070A in steps S6090A,S6060A and S6070A. To be specific, for example, when the output datainside the area estimated to have the solution has been acquired (Yes instep S6090), the search apparatus 300 specifies an optimal solution OS3in the estimation division area, and saves the estimated optimalsolution OS3 in the database 205 (step S606). In addition, when theoutput data inside the area estimated to have the solution has not beenacquired (No in step S6090), the search apparatus 300 executesautonomous search inside the estimated area (step S6060A), acquires theoutput data, that is, the search result inside the area estimated tohave the solution, and saves the acquired data in the database 205 (stepS6070A) in the same manner.

Thereafter, the search apparatus 300 determines whether a value of theoutput parameter according to the optimal solution OS3 is a solutioncloser to the target than the value of the output parameter according tothe optimal solution OS1 (step S607) similarly to step S511. Further,the process transitions to step S512 in a case where the value of theoutput parameter corresponding to the optimal solution OS3 is thesolution closer to the target than the value of the output parametercorresponding to the optimal solution OS1 (Yes in step S607), andtransitions to step S608 in the opposite case (No in step S607). In stepS608, the search apparatus 300 updates the search area by excluding theexclusion area from the search area or excluding the exclusion area andthe exclusion data (step S608), and the process transitions to stepS505.

FIG. 7 is a third flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus 201. The thirdflowchart is another processing example of the second flowchartillustrated in FIG. 6. Incidentally, the same process as that of FIG. 6will be denoted by the same step number, and will not be described.After step S601, the search apparatus 300 determines whether to excludethe exclusion data decided in step S601 (step S703). The processtransitions to step S604 when analysis is performed after performing theexclusion (Yes in step S703), and transitions to step S608 when theanalysis is performed without performing the exclusion (No in stepS703).

To be specific, for example, the search apparatus 300 determines whetherto perform the analysis after excluding the exclusion area depending onpresence or absence of an input of an exclusion instruction from theuser in step S703. In addition, the search apparatus 300 may perform theanalysis after forcibly excluding the exclusion data (Yes in step S703).

Thereafter, the search apparatus 300 generates a prediction model of thedivision area without using the exclusion data (step S604), and executessteps S605, S6090A, S6060A, S6070A, S606, S607, and S608.

FIG. 8 is a fourth flowchart illustrating a procedure example of thecontrol process of the semiconductor processing apparatus 201. Thefourth flowchart is still another processing example of the secondflowchart illustrated in FIG. 6. Incidentally, the same process as thatof FIG. 6 will be denoted by the same step number, and will not bedescribed. After step S602, the search apparatus 300 determines whetherto perform the analysis after excluding the exclusion area decided instep S602 (step S803). The process transitions to step S604 when theanalysis is performed after performing the exclusion (Yes in step S803),and transitions to step S608 when the analysis is performed withoutperforming the exclusion (No in step S803).

To be specific, for example, the search apparatus 300 determines whetherto perform the analysis after excluding the solution (value of the inputparameter) inside the exclusion area depending on presence or absence ofthe input of the exclusion instruction from the user in step S803. Inaddition, the search apparatus 300 may perform the analysis afterforcibly excluding the exclusion area (Yes in step S803).

Thereafter, the search apparatus 300 generates the prediction model ofthe division area (step S604) similarly to step S604. Next, the searchapparatus 300 estimates the division area where the solution is presentfrom a division area group divided in step S603 without using thesolution (value of the input parameter) inside the exclusion area (stepS605). The estimated division area is referred to as the estimationdivision area. Further, the search apparatus 300 executes steps S6090A,S6060A, S6070A, S606, S607, and S608.

Incidentally, when a scale of the analysis, saving, transmission and thelike of data increases in this control process so that the executiontime thereof becomes longer than the time to search one condition, it ispossible to continue the search in parallel with the execution of theseprocesses. At this time, one or more value is increased among the numberof input parameters to be changed in the search condition, the number ofinput parameters to be changed at the same time, and the number ofdivisions of the search area. Accordingly, when the number of searchconditions is increased and search is performed for these conditions, itis possible to increase the search results using the time for executingthe analysis and the like. In particular, there is a case where the timerequired for the analysis of data becomes several minutes to severalhours or longer, and it is possible to improve the search speed bycontinuing the search during the analysis.

<First Application Example of Control Process of SemiconductorProcessing apparatus 201>

Next, a description will be given regarding an application example ofthe control process, performed to correct an apparatus difference of thesemiconductor processing apparatus 201 in maintenance of thesemiconductor processing apparatus 201 performed before mass productionof the semiconductor device. Herein, the semiconductor processingapparatus 201 is assumed to be an etching apparatus that performs adischarging process as an example for describing a procedure ofapparatus difference suppression. In addition, an input parameter at thetime of executing the discharging process will be referred to as arecipe. In the etching apparatus that performs the discharging process,a processing result or discharging characteristics used in theprocessing are exemplified as output serving as an object to becorrected. A method of correcting another etching apparatus to obtainthe same output as that of an etching apparatus serving as a referenceor a method of performing correction such that outputs of a plurality ofetching apparatuses become even is used as a correction method.

FIG. 9 is a flowchart illustrating a method of suppressing an apparatusdifference. To be specific, for example, the search apparatus 300 startsacquisition of discharge data in FIG. 9 after maintenance in order toperform the apparatus difference correction representing a procedureexample of the process of maintaining the semiconductor processingapparatus 201 performed before the mass production of the semiconductordevice.

First, the search apparatus 300 performs reference recipe discharging inorder to perform a basic discharging process, and acquires input andoutput data at this time. In addition, discharging according to therecipe to be used in the mass production is performed, and output data(value of an output parameter) at this time is acquired (step S901).Step S901 is the process corresponding to steps S501 to S504.

Next, the search apparatus 300 searches an apparatus differencecorrection recipe (step S902). Step S902 is the process corresponding tosteps S505 to S507. Further, the search apparatus 300 executes theapparatus difference correction using the apparatus differencecorrection recipe searched in step S902 (step S903). Step S903 is theprocess corresponding to steps S508 to S513 and the processes in FIGS. 6to 8. The process returns to step S902 when a correction target has notbeen achieved (No in step S904), and the process is ended when thecorrection target has been achieved (Yes in step S904). Step S904 is theprocess corresponding to step S514.

Incidentally, the search speed may be improved by causing the search toproceed in parallel using a plurality of the same etching apparatuses.At this time, it is possible to enhance the possibility that thesolution that satisfies the target can be searched by employing theplurality of etching apparatuses from which the apparatus difference hasbeen corrected by the procedure in FIG. 9. Further, it is possible toperform the correction by loading the searched solution in the pluralityof apparatuses.

When the search method using the search apparatus 300 is executed afterthe maintenance of the semiconductor processing apparatus 201 in thismanner, it is possible to cause the value of the output parameter of thesemiconductor processing apparatus 201 to approximate to the value ofthe output parameter serving as the reference (automatic apparatusdifference correction function).

<Second Application Example of Control Process of SemiconductorProcessing Apparatus 201>

Next, a description will be given regarding an application example of acontrol process to correct a temporal change in the mass production ofthe semiconductor device process.

FIG. 10 is a flowchart illustrating a method of correcting the temporalchange. In FIG. 10, the semiconductor processing apparatus 201 isassumed to be the etching apparatus that uses discharging in processingas an example for describing a procedure of correcting the semiconductorprocessing apparatus 201, similarly to FIG. 9. In the discharge dataacquisition prior to the mass production, the search apparatus 300 firstassigns a reference recipe for the basic discharging process to theetching apparatus to perform the reference recipe discharging, andacquires output data (value of the output parameter) at this time inorder to perform the correction of the temporal change during the massproduction (step S1011). Step S1011 is the process corresponding tosteps S501 to S504.

Next, the search apparatus 300 searches an apparatus differencecorrection candidate recipe (step S1012). In step S1012, output data orsensor data and monitor data with which a temporal change of an objectto be corrected can be predicted is used based on an analysis result ofinput and output data in the past mass production. Further, the searchapparatus 300 executes the search of the apparatus difference correctioncandidate recipe to change these data with which the temporal change canbe predicted to values after being subjected to temporal change in theetching apparatus prior to starting of the mass production. Step S1012is the process corresponding to steps S505 to S507.

Next, the search apparatus 300 executes the apparatus differencecorrection (step S1013). In step S1013, the search apparatus 300compares a basic recipe for mass production, used in a state where thetemporal change is not generated, with the apparatus differencecorrection candidate recipe searched in step S1012, and confirms aninput parameter changed in the apparatus difference correction candidaterecipe. Accordingly, it is possible to generate a function to describe arelation between an input parameter and an output parameter of theobject to be corrected in a stage prior to the mass production, andfurther, it is possible to generate the recipe serving as the correctioncandidate based on the relation. Step S1013 is the process correspondingto steps S508 to S513 and the processes in FIGS. 6 to 8. Thereafter, themass production process is started.

When the mass production of the semiconductor device process is startedafter step S1013, a wafer is introduced into the processing chamber(step S1021), the etching apparatus etches the wafer (step S1022). Theetching (step S1022) is configured using one step or a plurality ofsteps. When the etching (step S1022) includes the plurality of steps,the etching of each step is executed by changing a discharge condition.After completion of the etching (step S1022), the wafer is carried outof the processing chamber (step S1023). Further, plasma cleaning isperformed to remove reaction products generated during the etching anddeposited on a surface of the processing chamber (step S1024). Theprocess returns to step S1021 when there is the next wafer (Yes in stepS1025), and transitions to the discharge data acquisition after the massproduction when there is no next wafer (No in step S1025).

The input and output data of the etching apparatus during the massproduction are saved in the database 205, and the search apparatus 300continues analysis of the input and output data in real-time in aparallel manner. Accordingly, it is possible to continue the estimationof the output data or the sensor data and the monitor data with whichthe temporal change of the object to be corrected can be predicted,during the mass production. In addition, the search apparatus 300 canincrease the number of data by integrating the input and output data ofthe plurality of etching apparatuses that execute the same massproduction process.

When the discharge data is acquired after the mass production or afterelapse of time designated from start of the mass production, the searchapparatus 300 executes the search of the recipe to correct the temporalchange (step S1031). To be specific, for example, the search apparatus300 uses the data acquired in steps S1011 and S1012, the relationbetween the analyzed input and output data, and the correction candidaterecipe as the input in step S502 to search a temporal change correctionrecipe. Step S1031 is the process corresponding to steps S505 to S507.

Further, the search apparatus 300 uses the temporal change correctionrecipe serving as a search result to perform verification of acorrection result (step S1032). Step S1032 is the process correspondingto steps S508 to S513 and the processes in FIGS. 6 to 8.

In addition, the search apparatus 300 may analyze the output dataacquired during the mass production of the semiconductor device,estimate the output data or the sensor data and the monitor data withwhich the temporal change of the object to be corrected can bepredicted, and execute step S1012 prior to the execution of steps S1031and S1032. Accordingly, it is possible to generate a function fordescribing the relation between the input parameter and the outputparameter of the object to be corrected, and further, to generate therecipe serving as the correction candidate based on the relation. Thesearch apparatus 300 can execute steps S1031 and S1032 using theseresults in step S502.

Further, a recipe obtained by changing an input parameter, which isfrequently used for correction, based on the knowledge of the engineer,input and output data and an analysis result thereof at the time ofperforming discharging using this recipe may be used as the input ofstep S502 in the above-described search.

Further, the process returns to step S1031 when a correction target hasnot been achieved (No in step S1033), and the process is ended when thecorrection target has been achieved (Yes in step S1033). Step S1033 isthe process corresponding to step S514. At the time of executing thesearch illustrated in FIG. 10, it is possible to improve the searchspeed by causing the search to proceed in parallel using the pluralityof etching apparatuses after being subjected to the mass production inwhich the same mass production process has been performed. Further, itis possible to execute the correction by loading the searched solution(input parameter) in the plurality of etching apparatuses that executethe same mass production process.

When the search method using the search apparatus 300 is executed afterthe mass production of the semiconductor in this manner, it is possibleto correct the temporal change of the value of the output parameter ofthe semiconductor processing apparatus 201 during the mass production(automatic temporal change correction function).

In this manner, the search apparatus 300 automatically analyzes thevalue of the input parameter and the value of the output parameter ofthe semiconductor processing apparatus 201, and automatically decidesthe experiment condition to search the value of the input parameter onconsideration of the analysis result thereof. Further, the searchapparatus 300 automatically performs verification of the experimentresult and can automatically search the value of the input parameterwith which the apparatus state and the processing result (value of theoutput parameter) serving as the target can be obtained by repeatingthese automatic operations. Accordingly, the semiconductor processingapparatus 201 itself can automatically draw out the apparatusperformance, and can support development of a control model to furtherdrawing-out of the apparatus performance and the engineer who selects anapparatus parameter (combination of the input parameter and the outputparameter).

As described above the search apparatus 300 according to the embodimentincludes: the input unit 401 that receives each input of a target value,which indicates a condition to be set in a semiconductor processingapparatus 201 to process a semiconductor or a result obtained byprocessing the semiconductor using the semiconductor processingapparatus 201, a reference value of the condition inside a search areadefined by ranges of the condition and the result, and the result, thereference value indicated by the target value; the generating unit 402that generates a prediction model indicating a relation between thecondition and the result based on a setting value of the conditioninside the search area, a measured value of the result obtained when thesetting value is assigned to the semiconductor processing apparatus 201;the specifying unit 403 that acquires a prediction value from theprediction model by assigning the target value input to the input unit401 to the prediction model generated by the generating unit 402, andspecifies a presence area of the prediction value from the search area;the determining unit 404 that determines whether the measured value ofthe result corresponding to the prediction value is closer to the targetvalue than the reference value input to the input unit 401; the settingunit 405 that sets the prediction value to the reference value when thedetermining unit 404 determines that the measured value of the resultcorresponding to the prediction value is closer to the target value, andsets the prediction value presence area specified by the specifying unitto the search area; and the output unit 406 that outputs a predictionvalue satisfying an achievement condition when the measured value of theresult corresponding to the prediction value satisfies the achievementcondition of the target value.

Accordingly, it is possible to improve the accuracy in achieving theoptimal solution that relates to the input and output of thesemiconductor processing apparatus 201. Accordingly, it is possible toachieve the efficiency in operation and optimization of processing ofthe semiconductor processing apparatus 201.

In addition, when the determining unit 404 determines that a measuredvalue of a result, which corresponds to a prediction value obtainedusing a prediction model, is not closer to a target value, the searchapparatus 300 causes the deciding unit 407 to decide a prediction valueinside a prediction value presence area and the measured value of theresult corresponding to the prediction value as exclusion data, andcauses the setting unit 405 to set a remaining area obtained byexcluding an exclusion area specified using exclusion data from a searcharea and the target value assigned to the semiconductor processingapparatus 201 when the exclusion data is obtained, as the search area.Accordingly, it is possible to exclude the exclusion area, which has acombination of a prediction value that is not close to a target valueand the target value, from the latest search area, and to achieve theimprovement of the accuracy in achieving the optimal solution.

In addition, the search apparatus 300 causes the dividing unit 408 todivide the search area into a plurality of areas and causes thespecifying unit 403 to set the prediction value to a reference value tospecify the prediction value presence area from a plurality of divisionareas when the determining unit 404 detects that the measured value ofthe result corresponding to the prediction value is closer to the targetvalue.

Accordingly, it is possible to easily specify the prediction valuepresence area and to achieve the improvement of the search speed.

In addition, the search apparatus 300 causes the dividing unit 408 todivide the search area into a plurality of areas, causes the generatingunit 402 to acquire the measured value of the result, obtained when thecondition setting value inside a division area is assigned to thesemiconductor processing apparatus 201, for each division area, andcauses the generating unit 402 to generate a prediction model based onthe condition setting value and the measured value of the result in eachof the division areas. Accordingly, it is possible to acquire themeasured value for each of the division areas, and to increase thegeneration rate of the prediction model using the plurality ofsemiconductor processing apparatuses 201.

In addition, when the determining unit 404 determines that the measuredvalue of the result corresponding to the prediction value is not closerto the target value, the search apparatus 300 causes the deciding unit407 to decide data acquired inside the prediction value presence area asexclusion data, causes the generating unit 402 to generate a predictionmodel based on a specific measured value obtained by excluding theexclusion data from the measured value and a specific setting valueobtained by excluding a setting value, assigned to the semiconductorprocessing apparatus 201 when the exclusion data is obtained, from thesetting value. In addition, it is possible to exclude the exclusionarea, which has a combination of a prediction value that is not close toa target value and the setting value, from a candidate of the predictionvalue, and to achieve the improvement of the accuracy in the predictionmodel. Accordingly, it is possible to obtain a more favorable predictionvalue using the generated prediction model.

In addition, the search apparatus 300 causes the detecting unit 409 todetect an unstable operation of the semiconductor processing apparatus201 based on the measured value of the result and a predetermined outputthreshold value, and causes the output unit 406 to output a detectionresult obtained by the detecting unit 409. Accordingly, it is possibleto urge the user to decide whether to continue the search.

Incidentally, the present invention is not limited to theabove-described embodiments, and may include various modifications andequivalent configurations within a gist of the range of the appendedclaims. For example, the above-described embodiments have been describedin detail in order to describe the present invention in an easilyunderstandable manner, and the present invention is not necessarilylimited to one including the entire configuration that has beendescribed above. In addition, a part of the configuration of a certainembodiment may be replaced with the configuration of another embodiment.In addition, the configuration of a certain embodiment may be added withthe configuration of another embodiment. In addition, addition, deletionor substitution of other configurations may be made with respect to someconfigurations of each embodiment.

In addition, each configuration, function, processing unit, processingmeans, and the like described above may be, partially or fully,implemented by hardware, for example, by designing it using anintegrated circuit and the like, or implemented by software by causingthe processor to interpret and execute a program that implements eachfunction.

The information, such as a program, a table, and a file, to implementeach function can be stored in a storage device, such as a memory, ahard disk, and an SSD (Solid State Drive), or a recording medium such asan integrated circuit (IC) card, an SD card, and a digital versatiledisc (DVD).

In addition, only a control line and an information line considered tobe necessary for the description are illustrated, and all control linesand information lines required for implementation are not illustrated.It may be considered that most of configurations are practicallyconnected to each other.

What is claimed is:
 1. A search apparatus comprising: an input unit thatreceives each input of a target value, which indicates a condition to beset in a semiconductor processing apparatus to process a semiconductoror a result obtained by processing the semiconductor using thesemiconductor processing apparatus, a reference value of the conditioninside a search area defined by ranges of the condition and the result,and the result, the reference value indicated by the target value; agenerating unit that generates a prediction model indicating a relationbetween the condition and the result based on a setting value of thecondition inside the search area, a measured value of the resultobtained when the setting value is assigned to the semiconductorprocessing apparatus; a specifying unit that acquires a prediction valuefrom the prediction model by assigning the target value input to theinput unit to the prediction model generated by the generating unit, andspecifies a presence area of the prediction value from the search area;a determining unit that determines whether the measured value of theresult corresponding to the prediction value is closer to the targetvalue than the reference value input to the input unit; a setting unitthat sets the measured value of the result corresponding to theprediction value to the reference value when the determining unitdetermines that the measured value of the result corresponding to theprediction value is closer to the target value, and sets the predictionvalue presence area specified by the specifying unit to the search area;and an output unit that outputs a prediction value satisfying anachievement condition when the measured value of the resultcorresponding to the prediction value satisfies the achievementcondition of the target value.
 2. The search apparatus according toclaim 1, further comprising a deciding unit that decides the predictionvalue inside the prediction value presence area and the measured valueof the result corresponding to the prediction value as exclusion datawhen the determining unit determines that the measured value of theresult corresponding to the prediction value is not closer to the targetvalue, wherein the setting unit sets a remaining area obtained byexcluding an exclusion area, which is specified based on the exclusiondata decided by the deciding unit and a target value assigned to thesemiconductor processing apparatus when the exclusion data is obtained,from the search area as the search area.
 3. The search apparatusaccording to claim 1, further comprising a dividing unit that dividesthe search area into a plurality of areas, wherein the specifying unitsets the prediction value to the reference value when the determiningunit determines that the measured value of the result corresponding tothe prediction value is closer to the target value, and specifies theprediction value presence area, specified by the specifying unit, amonga plurality of division areas obtained by the dividing unit.
 4. Thesearch apparatus according to claim 1, further comprising a dividingunit that divides the search area into a plurality of areas, wherein thegenerating unit acquires the measured value of the result, obtained whenthe condition setting value inside the division area obtained by thedividing unit is assigned to the semiconductor processing apparatus, foreach of the division areas, and generates the prediction model based onthe condition setting values in the respective division areas and themeasured value of the result.
 5. The search apparatus according to claim1, wherein the setting unit sets the prediction value presence area tothe search area when the determining unit determines that the measuredvalue of the result corresponding to the prediction value is not closerto the target value, instead of setting the measured value of the resultcorresponding to the prediction value to the reference value.
 6. Thesearch apparatus according to claim 1, further comprising a decidingunit that decides the prediction value inside the prediction valuepresence area and the measured value of the result corresponding to theprediction value as exclusion data when the determining unit determinesthat the measured value of the result corresponding to the predictionvalue is not closer to the target value, wherein the generating unitgenerates the prediction model based on a specific measured valueobtained by excluding the exclusion data from the measured value and aspecific setting value obtained by excluding a setting value, assignedto the semiconductor processing apparatus when the exclusion data isobtained, from the setting value.
 7. The search apparatus according toclaim 1, further comprising a detecting unit that detects an unstableoperation of the semiconductor processing apparatus based on themeasured value of the result and a predetermined output threshold value,wherein the output unit outputs a detection result obtained by thedetecting unit.
 8. The search apparatus according to claim 1, thesetting unit sets central condition of the condition which assigns tothe prediction model, wherein the specifying unit that acquires theprediction value from the prediction model generated by the generatingunit, by assigning the central condition set by the setting unit to theprediction model, and specifies a presence area of the prediction valuefrom the search area.
 9. The search apparatus according to claim 8,wherein the setting unit that designates the number of types of thecondition which is changeable once from the central condition.
 10. Thesearch method that is executed by a search apparatus, the searchapparatus executes: an input process of receiving each input of a targetvalue, which indicates a condition to be set in a semiconductorprocessing apparatus to process a semiconductor or a result obtained byprocessing the semiconductor using the semiconductor processingapparatus, a reference value of the condition inside a search areadefined by ranges of the condition and the result, and the result, thereference value indicated by the target value; a generating process ofgenerating a prediction model indicating a relation between thecondition and the result based on a setting value of the conditioninside the search area, a measured value of the result obtained when thesetting value is assigned to the semiconductor processing apparatus; aspecifying process of acquiring a prediction value from the predictionmodel by assigning the target value input in the input process to theprediction model generated in the generating process, and specifying apresence area of the prediction value from the search area; adetermining process of determining whether the measured value of theresult corresponding to the prediction value is closer to the targetvalue than the reference value input in the input process; a settingprocess of setting the measured value of the result corresponding to theprediction value to the reference value when it is determined that themeasured value of the result corresponding to the prediction value iscloser to the target value in the determining process, and setting theprediction value presence area specified in the specifying process tothe search area; and an output process of outputting a prediction valuesatisfying an achievement condition when the prediction value satisfiesthe achievement condition of the target value.
 11. The search methodaccording to claim 10, the search apparatus further executes a decidingprocess of deciding the prediction value inside the presence area andthe measured value of the result corresponding to the prediction valueas exclusion data when it is determined that the measured value of theresult corresponding to the prediction value is not closer to the targetvalue in the determining process, wherein, in the setting process, thesearch apparatus sets a remaining area obtained by excluding anexclusion area, which is specified based on the exclusion data decidedin the deciding process and a target value assigned to the semiconductorprocessing apparatus when the exclusion data is obtained, from thesearch area as the search area.
 12. The search method according to claim10, the search apparatus further executes a dividing process of dividingthe search area into a plurality of areas, wherein, in the specifyingprocess, the search apparatus sets the prediction value to the referencevalue when it is determined that the measured value of the resultcorresponding to the prediction value is closer to the target value inthe determining process, and specifies the prediction value presencearea, specified in the specifying process, among a plurality of divisionareas obtained in the dividing process.
 13. The search method accordingto claim 10, the search apparatus further executes a dividing process ofdividing the search area into a plurality of areas, wherein, in thegenerating process, the search apparatus acquires the measured value ofthe result, obtained when the condition setting value inside thedivision area obtained in the dividing process is assigned to thesemiconductor processing apparatus, for each of the division areas, andgenerates the prediction model based on the condition setting values inthe respective division areas and the measured value of the result. 14.The search method according to claim 10, wherein in the setting process,the search apparatus sets the prediction value presence area to thesearch area when it is determined that the measured value of the resultcorresponding to the prediction value is not closer to the target valuein the determining process, instead of setting the prediction value tothe reference value.
 15. The search method according to claim 10, thesearch apparatus further executes a deciding process of deciding theprediction value inside the prediction value presence area and themeasured value of the result corresponding to the prediction value asexclusion data when it is determined that the measured value of theresult corresponding to the prediction value is not closer to the targetvalue in the determining process, wherein, in the generating process,the search apparatus generates the prediction model based on a specificmeasured value obtained by excluding the exclusion data from themeasured value and a specific setting value obtained by excluding asetting value, assigned to the semiconductor processing apparatus whenthe exclusion data is obtained, from the setting value.
 16. The searchmethod according to claim 10, the search apparatus further executes adetecting process of detecting an unstable operation of thesemiconductor processing apparatus based on the measured value of theresult and a predetermined output threshold value, wherein, in theoutput process, the search apparatus outputs a detection result obtainedin the detecting process.
 17. The search method according to claim 10,wherein, in the setting process, the search apparatus sets centralcondition of the condition which assigns to the prediction model,wherein, in the specifying process, the search apparatus acquires theprediction value from the prediction model generated by the generatingprocess, by assigning the central condition set by the setting processto the prediction model, and specifies a presence area of the predictionvalue from the search area.
 18. The search method according to claim 17,wherein, in the setting process, the search apparatus designates thenumber of types of the condition which is changeable once from thecentral condition.